Which 1st Term US Senator Will Lose in 2018?

At least one first-term incumbent has been defeated in 48 of the 52 election cycles during the direct election era

It may have come as a surprise that only two U.S. Senators running for reelection in 2016 were defeated, with Donald Trump’s stronger than expected performance aiding the candidacies of Republicans like Roy Blunt of Missouri, Richard Burr of North Carolina, Pat Toomey of Pennsylvania, and Ron Johnson of Wisconsin.

However, the fact that one of the two incumbents to fall was a first-term senator – Kelly Ayotte of New Hampshire – was perhaps less of a shock. [Illinois’ Mark Kirk, the other failed incumbent in 2016 was not a true first-term member of the chamber, having served for two months at the end of the 109th Congress after winning 2010’s special election].

Not surprisingly, over the decades it has been the institution’s greenest members – incumbents in their first term – who have suffered the greatest turnover of their seats.

That may also be the case in 2018 when some of the most vulnerable senators on the ballot are currently serving in their first term such as Democrats Joe Donnelly of Indiana, Heidi Heitkamp of North Dakota, and Tammy Baldwin of Wisconsin.

In total there are 13 true first-term U.S. Senators up for election in 2018, not including Nevada GOPer Dean Heller who was appointed in 2011 but will be facing his first reelection bid.

And so while first-term U.S. Senators usually account for much less than half of the number of incumbents on a given cycle’s ballot, they have historically been in the majority of those who have failed in keeping their seats.

Smart Politics reviewed the nearly 1,900 U.S. Senate elections conducted since 1914 and found that 52 percent of defeated incumbents were in their first term, with at least one first term U.S. Senator losing in 48 of the 52 election cycles since 1914.

Overall, 359 U.S. Senators have been defeated across the more than 1,875 special and general elections conducted during the last 52 cycles since 1914 after the passage of the 17th Amendment.

Of these 359 incumbents, 189 were in their first-term, or 52.4 percent of those who fell in defeat at either the nomination or general election phase.

[Note: This tally does not include an additional 11 U.S. Senators who were elected to one term, were then appointed just a few days or weeks prior to the start date of that term, and were then defeated when seeking what was technically a third term, not a second. This practice (to boost seniority over fellow classmates) is no longer practiced in the chamber.].

Over the past century, an average of 3.6 first-term U.S. Senators have gone down to defeat per cycle, with at least one losing in 48 of these 52 election cycles since 1914.

The only cycles in which a first-term incumbent did not suffer such a defeat were in 1960, 1990, 2004, and 2010 – cycles in which there was a relatively low number of those seeking reelection for the first time: seven in 1960, eight in 1990, six in 2004, and eight in 2010.

By contrast, there were a dozen first-term U.S. Senators seeking reelection in 2012, 14 in 2014, 15 in 2016, and 13 are expected to do so in 2018.

Over the decades, there has been a notable change in the number of U.S. Senators who have been defeated at the ballot box.

For example, for the first 50 years of direct elections from 1914 through 1964, a total of 232 U.S. Senators were defeated in their quest for another term, or 8.9 per cycle.

Over the last 50 years since 1966, that number has dropped to 4.9 per cycle (127 senators).

The cycle with the largest number of defeated incumbents overall came after the Great Depression during the Democratic landslide of 1932 when 14 U.S. Senators were sent packing. Just four of those were in their first term: Democrat Walter Walker of Colorado and Republicans John Thomas of Idaho, Otis Glenn of Illinois, and John Blaine of Wisconsin.

The most first-term incumbents to suffer defeat came in 1918 with 10: Republican John Weeks of Massachusetts and Democrats John Shafroth of Colorado, Willard Saulsbury of Delaware, Thomas Hardwick of Georgia, J. Hamilton Lewis of Illinois, William Thompson of Kansas, James Vardaman of Mississippi, Xenophon Wilfley of Missouri, Henry Hollis of New Hampshire, and Christie Benet of South Carolina.

Nine lost in 1916 and 1926 with eight in 1930, and seven in 1922, 1938, 1942, and 1946.

No more than five first-term incumbents have lost in any election cycle since the 1950s.

First-term U.S. Senators accounted for 58.6 percent of defeated senators from 1914 to 1964 (136 of 232), but have dropped a bit to 41.7 percent from 1966 to 2016 (53 of 127).

Over the last quarter-century, 14 of the 22 defeated first-term U.S. Senators have been Republicans:

• 1992: Georgia Democrat Wyche Fowler and California Republican John Seymour
• 1994: Pennsylvania Democrat Harris Wofford
• 1996: Kansas Republican Sheila Frahm
• 1998: Illinois Democrat Carol Mosely-Braun and North Carolina Republican Lauch Faircloth
• 2000: Republicans Spence Abraham of Michigan, John Ashcroft of Missouri, and Rod Grams of Minnesota
• 2002: Arkansas Republican Tim Hutchinson, Georgia Democrat Max Cleland, and Missouri Democrat Jean Carnahan
• 2006: Republicans Jim Talent of Missouri and George Allen of Virginia
• 2008: Republicans Norm Coleman of Minnesota, John Sununu of New Hampshire, and Elizabeth Dole of North Carolina
• 2012: Massachusetts Republican Scott Brown
• 2014: Democrats Mark Begich of Alaska, Kay Hagan of North Carolina, and Mark Udall of Colorado
• 2016: New Hampshire Republican Kelly Ayotte

Other first-term incumbents who cannot take their path to victory for granted in 2018 include Arizona Republican Jeff Flake and Virginia Democrat Tim Kaine.

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